Anaphy Quiz 2 (Urinary) Flashcards
Structural and functional unit of kidneys
Nephrons
Two main structures of each nephron:
- Renal Corpuscle
- Renal tubule
Renal corpuscle consists of what
- Glomerulus
- Bowman’s Capsule/Glomerular Capsule
What makes up the Glomerulus
Podocytes
A knot of capillaries found in the renal corpuscle of nephrons
Glomerulus
A cupshaped structure that surrounds the glomrulus
Glomerular (Bowman’s) capsule
What are the subdivisions of the Renal Tubule:
- Proximal convoluted tubule (PCT)
- Nephron loop (loop of Henle)
- Distal convoluted tubule (DCT)
a. Where does the Renal tubule start?
b. Where does it end?
a. Glomerular (Bowman’s) Capsule
b. Collecting Duct
These nephrons are located entirely in the cortex
Cortical nephrons
Most nephrons are located here
Cortical nephrons
Found at the cortex-medulla junction
Juxtamedullary nephrons
Two capillary beds associated with each nephron
- Glomerulus
- Peritubular capillary bed
Glomerulus is fed and drained by what?
Arterioles
Arises from a cortical radiate artery and feeds the glomerulus
Afferent Arteriole
Receives blood that has passed
through the glomerulus
Efferent Arteriole
Where does the Peritubular capillary bed arise?
Efferent Arteriole
These are low-pressure, porous capillaries that are adapted for absorption in the nephron
Peritubular capillary beds
Where does Peritubular capillary beds drain?
Interlobar veins
Water and solutes smaller than proteins are forced through the
capillary walls and pores of the glomerular
capsule into the renal tubule.
Glomerular filtration:
Urine formation is the result of three processes, what are these 3 processes?
- Glomerular filtration
- Tubular reabsorption
- Tubular secretion
Water, glucose,
amino acids, and needed ions are
transported out of the filtrate into the tubule
cells and then enter the capillary blood.
Tubular reabsorption
H1, K1, creatinine, and
drugs are removed from the peritubular blood
and secreted by the tubule cells into the
filtrate
Tubular secretion
What substances are “too large” to pass through the filtration membrane?
Proteins and blood cells
Once in the capsule, the fluid is called a what
Filtrate
Filtrate leaves via the?
Renal Tubule
Is filtration a nonselective or selective passive process?
Nonselective
The peritubular capillaries reabsorb useful substances
from the renal tubule cells, such as:
▪ Water
▪ Glucose
▪ Amino acids
▪ Ions
Where do most reabsorption occur
Proximal Convoluted tubule
Is reabsorption mostly passive or active?
Mostly active
Some materials move from the blood of the peritubular
capillaries into the renal tubules to be eliminated in
filtrate, what are these materials?
▪ Hydrogen and potassium ions
▪ Creatinine
Secretion is important for:
(just reveal answer)
▪ Getting rid of substances not already in the filtrate
▪ Removing drugs and excess ions
▪ Maintaining acid-base balance of blood
Most important trigger for aldosterone release
Renin-angiotensin mechanism
Renin-angiotensin mechanism is mediated by what
Juxtaglomerular (JG) apparatus
Renin-angiotensin mechanism:
(Just Reveal Answer)
Renin -> Angiotensin II -> causes vasoconstriction -> release of Aldosterone
Result: Increase in blood volume and pressure
Cells of the JG apparatus are stimulated by what? Allowing the enzyme to be released into the blood
Low Blood Pressure
Formation of glomerular filtrate
Glomerulus
Reabsorption of 65% of filtered Na/K/Ca and Mg; 85% of NaHCO3, and nearly 100% of glucose and amino acids. Isosmotic reabsorption of water
Proximal Convoluted Tubule
Secretion and reabsorption of organic acids and bases, including uric acid and most diuretics
Proximal Tubule, straight segments
Passive reabsorption of water
Thin descending limb of Henle’s loop
Active reabsorption of 15–25% of filtered Na/K/Cl; secondary reabsorption of Ca and Mg
Thick ascending limb of Henle’s Loop (TAL)
Active reabsorption of 4-8% of filtered Na and Cl; Ca reabsorption under parathyroid hormone control
Distal Convoluted tubule (DCT)
Na reabsorption (2-5%) coupled to K and H secretion
Cortical Collecting tubule (CCT)
Water reabsorption under vasopressin control
Medullary collecting duct
